Online Dictionary of Invertebrate Zoology: Complete Work - Best Text

Rrace n. [F. race; member of the same stock or lineage] Apopulation or aggregate of populations inhabiting a definedgeographical and/or ecological region possessing characteristicphenotypic and gene frequencies or features ofchromosome structures that distinguish it from other suchgroups.racemose a. [L. racemus, bunch] Bunch, as perhaps of grapes.racemose glands (SIPUN) Glandular structures on each side ofthe rectum; function unknown; buschelformigen Korper.rachidian, rhacidian a. [Gr. rhachis, backbone] (MOLL) Themedian or central tooth on the radula; the rachidian tooth.rachiform a. [Gr. rhachis, backbone; L. forma, shape] Shapedlike a rachis.rachiglossate, rhachiglossate a. [Gr. rhachis, backbone;glossa, tongue] (Moll) A radula with three longitudinal rowsof teeth: one median (may be simple or have severalcusps) and two lateral (rake-like with many cusps).rachis n.; pl. rachides, rachises [Gr. rhachis, backbone] 1.Any of various axial structures. 2. (NEMATA) The central oraxial chord in the ovary around which multiple rows ofgerminal cells are laid down.radial a. [L. radial, ray] 1. Extending from a center toward theperiphery like rays. 2. Pertaining to a radius.radial n. [L. radial, ray] (ECHINOD) 1. In Crinoidea, any proximal,undivided plate or ray bearing an anal plate. 2. InAsteroidea, a prominent ossicle on the surface in line withthe mid-line of the arm; part of the primary surface. 3. InEchinoidea, the ambulacrum.radial apophysis (ARTHRO: Chelicerata) In Arachnida, a copulatoryorgan on the male palp.radial canal (CNID: Scyphozoa) A canal in the mesoglea of amedusa running from the center to the edge, or at least inpart.